Abstract
Construction of the Facility Lidar for Astronomical Measurement of Extinction (FLAME) and the Astronomical Extinction SpectroPhotometer (AESoP) is nearing completion. FLAME is a 0.5m multi-wavelength backscatter lidar operating at the first three Nd:YAG harmonics and measuring with high precision and accuracy the Rayleigh backscatter from the middle stratosphere. AESoP is a 100mm diameter objective stellar spectroradiometer, the throughput of which is carefully calibrated to NIST radiometric standards. Together they form the core of the mobile instrument suite being amalgamated by the UNM Measurement Astrophysics group to characterize and calibrate atmospheric extinction at observatory sites. The first task of this instrument suite will be to help create a new set of standard stars radiometrically calibrated to NIST standards. Initially this will be done for bright stars across the wavelength range 350nm to 1050nm at 1nm spectral resolution with measurement accuracy better than 1% per spectral resolution element by calibration to NIST silicon detectors. The byproduct of these measurements is calibrated atmospheric transmission along the line of sight to the standard star.
Two New Instruments to Calibrate the Visible Sky
Construction of the Facility Lidar for Astronomical Measurement of Extinction (FLAME) and the Astronomical Extinction SpectroPhotometer (AESoP) is nearing completion. FLAME is a 0.5m multi-wavelength backscatter lidar operating at the first three Nd:YAG harmonics and measuring with high precision and accuracy the Rayleigh backscatter from the middle stratosphere. AESoP is a 100mm diameter objective stellar spectroradiometer, the throughput of which is carefully calibrated to NIST radiometric standards. Together they form the core of the mobile instrument suite being amalgamated by the UNM Measurement Astrophysics group to characterize and calibrate atmospheric extinction at observatory sites. The first task of this instrument suite will be to help create a new set of standard stars radiometrically calibrated to NIST standards. Initially this will be done for bright stars across the wavelength range 350nm to 1050nm at 1nm spectral resolution with measurement accuracy better than 1% per spectral resolution element by calibration to NIST silicon detectors. The byproduct of these measurements is calibrated atmospheric transmission along the line of sight to the standard star.